If so, you should immediately get the car looked at. It could be that your head gasket has blown, where a crack forms in the mating seal between the top and bottom parts of your engine.

A damaged head gasket allows coolant to get into the cylinder bores, contaminate your oil and even let highly pressurized gases back into the coolant system. These can all spell huge repair bills and depending on the cars value, a written off the engine.

The only true way to repair a head gasket leak is to replace the gasket, which itself typically only costs around $30. However, the labour to replace the gasket is time-consuming, requiring the mechanic to dismantle a lot of the engine and follow technical rebuild procedures, even having to machine parts of the engine flat. The bill could be as much as $3,000.

What is K&W Head Gasket Sealer or Fiberlock?

K&W Head Gasket Sealer, also called Fiberlock is made from a combination of water, sodium silicate, ceramic fibers, and cellulose copper. It is designed to cure head gasket leaks and is safe to use in all types of water cooled engines.

Apparently, K&W are using nanotechnology and military grade fibers in order to achieve proper seals. Interestingly, unlike other available products, K&W say this will also work on:

Intake gaskets

cylinder heads

coolant plugs

How easy is it to use?

However, there is conflicting information about how to use it, with the company website stating that for best results, coolant should be drained from the cooling system and then refilled with this product and water. After 500 miles, you are supposed to then replace the antifreeze according to your owners manual.

When working on the coolant system, you must always bleed the system, removing excess air for it to operate properly.

What do other people say about K&W Fiberlock?

Mixed results really. Some customers are happy, it fixed their blown gaskets and they appreciated the double your money back guarantee. It is noted that this product is cheaper than some of its competitors.

However, a number of other reviewers found that it blocked up their cooling system, causing their engine to overheat.

Should I buy Fiberlock by K&W?

That depends. If you cannot find any other gasket sealers and this is all that’s available to you, then yes by all means. It might work for you. It is also significantly cheaper than most of its competitors.

We wouldn’t recommend this product to others like Steel Seal and Blue Devil. Most Walmarts stock fiber look, so in a pinch, you might have to use it. Let us know how you get on.